Here are a couple of recent pictures of the 4-65a EIMAC under test. What an attractive glow!
A beautiful thoriated-tungsten glow
All about electronic valves and hi-fi
Here are a couple of recent pictures of the 4-65a EIMAC under test. What an attractive glow!
Hi. When you say a “Thoriated Tungsten Glow”, it might need some clarification.
Whether the Cathode is directly heated, (the glowing heater IS the Cathode), or
indirectly heated, (the heater heats the Cathode in close proximity), the ‘Thorium’
component of either, has nothing to do with the temperature, or the glow. That is
just due to the tungsten alone, with a high melting point. The ‘Thorium’, since quite
early development, was added to the Tungsten, as it results in a much greater flow
of electrons from the heated Cathode, (Thoriated Cathode, or Thoriated heater),
making it much more efficient.
But yes, they look good !!, and many old audio guys swear by valve technology
for warmth and clarity, as opposed to solid-state or digital production.
However, that’s a whole ‘nother’ argument !! Keep the glass fires burning…..
Hi Glenn, thank you for your insight on the tungsten filaments. Much appreciated
Thanks Ale…
I wasn’t trying to be picky… and i love the devices myself !
Just read your ‘About’ page, and it pretty much sums me up haha.
Was researching chemistry, and found a link to your site, which brought back memories. I’m now a 60-year-old, and worked for years as a technician, and remember fondly the days of playing with old vlave equipment, and marvelling at that wonderous glow!!!
Where i think you come in artistically as well, is how i saw these old components. They were not only functional, but were physical works or art in their own right !! especially some of the large complex ‘glassware’ that i had accumulated. Firing them up and making them ‘work’ again was a joy, and seeing your photos brought some of it back !
Glenn
Western Australia